1. Field of the Invention
The present invention relates to a motor vehicle including a subframe mounted on a vehicle body frame, and left and right suspensions supported on the subframe, and particularly, to a structure of such a subframe.
2. Description of the Prior Art
There is such a conventionally known subframe structure described in Japanese Patent Application Laid-open No. 193519/93.
This subframe includes two front and rear members coupled to each other into a hollow frame-like configuration by bolts, and a plurality of brackets mounted on left and right opposite sides thereof for supporting suspension arms.
Such a known subframe has the following problem:
A load from a rear wheel is transmitted through the suspension arm to the subframe which supports the suspension. Therefore, if the subframe does not have enough rigidity to withstand such a load, the performance of the suspension is not sufficiently exhibited. However, it can not be said that the above known subframe has sufficient rigidity, because it is formed into a mere hollow frame-like configuration.
In order to reinforce the subframe, it seems a good idea to interconnect, by cross-members, longitudinally intermediate portions of left and right side-members constituting the subframe. However, such a construction is accompanied by a disadvantage in that the cross-members become obstacles in mounting a fuel tank or the like in an internal space in the subframe.
The above known subframe also has another problem in that the bracket are mounted in correspondence to the suspension arms and hence, a large number of the brackets are required, resulting not only in an increased number of parts and an increased number of assembling steps, but also in a difficulty for providing a positional accuracy between points for supporting the suspensions.